Bump dev.langchain4j:langchain4j-agentic

Bumps [dev.langchain4j:langchain4j-agentic](https://github.com/langchain4j/langchain4j) from 1.5.0-beta11 to 1.6.0-beta12.
- [Release notes](https://github.com/langchain4j/langchain4j/releases)
- [Commits](https://github.com/langchain4j/langchain4j/commits)

---
updated-dependencies:
- dependency-name: dev.langchain4j:langchain4j-agentic
  dependency-version: 1.6.0-beta12
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -94,7 +94,7 @@
         <version.org.hibernate.validator>9.0.1.Final</version.org.hibernate.validator>
         <version.org.glassfish.expressly>6.0.0</version.org.glassfish.expressly>
         <!-- Experimental modules from langchain4j -->
-        <version.dev.langchain4j.beta>1.5.0-beta11</version.dev.langchain4j.beta>
+        <version.dev.langchain4j.beta>1.6.0-beta12</version.dev.langchain4j.beta>
         <!-- Base langchain4j version -->
         <version.dev.langchain4j>1.5.0</version.dev.langchain4j>